During the past year we have found evidence which indicates that brain polysome disaggregation in hyperphenylalaninemia is not caused by the accumulation of phenylethylamine, deficiency in cerebral ATP, nor liberation of ribonuclease from subcellular organelles. Hyperthermia was found to produce profound elevation in levels of brain amino acids and complete disaggregation of brain polysomes. We will attempt to determine the relationship between these effects and the causal mechanisms. Work will focus upon hyperthermia as a new model of aminoacidopathies. BIBLIOGRAPHIC REFERENCE: Calcium-Binding Proteins in Electroplax and Skeletal Muscle. Comparison of the Parvalbumin and Phosphodiesterase Activator Protein of Electrophorus electricus, S.R. Childers and F.L. Siegel (1976) Biochem. Biophys. Acta 439, 316-325.